1. Field of the Invention
The present invention relates to semiconductor devices and more particularly to mounting of discrete semiconductor devices.
2. Description of the Prior Art:
The present invention is directed to a semiconductor device incorporating a semiconductor element which is provided with a housing having at least a base member, a top member and an insulator member which connects the base and top members, the housing having enclosed within it a semiconducting element which is clamped in place between two electrodes by means of at least one spring, the semiconducting element being electrically connected to the electrodes by a thin layer of soft solder, the semiconductor device being provided with a current supply lead which is in contact with at least one of the exterior faces of the housing.
A semiconductor arrangement of this type has been described, for example, in German Pat. No. 1,439,304. In that arrangement, the semiconductor element is connected on one side via a layer of soft solder to an electrode and, on the other side, via a layer of soft solder, to the base member of the housing which serves as another electrode. The semiconductor is clamped between the electrodes by means of a saddle spring located in the housing. The outside face of the housing wall is provided with grooves which become deformed on being pressed into a recess in a current supply lead or into a cooling body or heat sink, thereby providing a lower electrical resistance and lower resistance to heat transfer.
The above-mentioned type of union between the housing and the current supply lead or heat sink is, however, relatively expensive on account of the relative hardness of the housing wall. In addition, the above-described type of union is difficult to release because, when inserting the housing in the above-mentioned recess, cold-welding takes place with the material constituting the current supply lead.
A simple releasable joint between a housing and a current-supply member or a heat sink is described, for example, in German Patent No. 1,276,209. In the arrangement described, a flat face of the housing abuts against an equally flat face of a supply electrode and is held firmly against the latter under high pressure by means of a spring. At the same time, the spring provides the interior contact pressure between the semiconductor element and the housing.
However, as far as the above-mentioned semiconductor arrangement with its soft solder layers subjected to pressure is concerned, this solution can only be employed when a separate spring system is employed for providing the interior and exterior contact pressures, because the solder layer can only endure an appreciably lower pressure than is necessary for the outside contact.